1. Field of the Invention
The invention relates to a sight device, in particular a reflector sight or telescopic sight, which comprises a lighting apparatus for generating or illuminating a target mark, wherein the lighting apparatus comprises an light guide made from photoluminescent, in particular fluorescent material and a radioluminescent light source coupled to the light guide, wherein the light guide is designed to receive ambient light along at least one section of its longitudinal extension and convert it into photoluminescent light, and wherein the absorption spectrum of the photoluminescent material of the light guide and the emission spectrum of the radioluminescent light source in the visible range can both be characterized respectively by a spectral bandwidth and a center wavelength.
2. Description of the Related Art
Known sight devices use ambient light (daylight) in order to produce or illuminate a target mark, also referred to as a reticle, e.g. in the form of a crosshair, scale or a point. The ambient light is captured by means of a light bus cable and converted by a photoluminescent dye in the light bus cable into fluorescent and/or phosphorescent light.
In order to obtain a target mark with sufficient brightness at night or at dusk, known sight devices have a radioluminescent light source, the light of which is fed into the light guide and is also converted there into photoluminescent light.
The photoluminescent light produced by the light guide can now be directed or reflected into the beam path of the sight device. In other sight devices the photoluminescent light can illuminate an already existing target mark, e.g. a front sight and/or rear sight.
EP 0 830 559 B1 discloses a sight device with a light bus cable and a trigalight connected to the light bus cable as a radioluminescent light source.
The disadvantage of such lighting apparatuses is that because of insufficient light from the conversion of light into fluorescent light a radioluminescent light source with greater light intensity needs to be selected. This increases not only the cost but also the space required for larger radio light sources. The main problem is that light easily visible to the human eye, e.g. in the green wavelength range, requires the stimulation of suitable fluorescent dyes in the blue or violet range. The production of a sufficient amount of stimulation light of this initially dark color would require a space-occupying (light source of suitably large dimensions) and complex construction (feeding the stimulation light into the light guide with as little loss as possible). Particularly in sight devices only very limited space is available, so that this problem has not yet been solved satisfactorily.